regulator: Add support for a fixed delay after voltage increases

index b1cef47..ed69fdc 100644
@@ -2801,7 +2801,9 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 		ret = -EINVAL;
 	}
 
-	if (ret != 0 || rdev->constraints->ramp_disable)
+	if (ret != 0 ||
+		(rdev->constraints->ramp_disable &&
+			!rdev->constraints->settle_time_up))
 		goto no_delay;
 
 	if (rdev->desc->ops->set_voltage_time) {

@@ -3050,25 +3052,27 @@ EXPORT_SYMBOL_GPL(regulator_set_voltage_time);
  * Provided with the starting and ending voltage, this function calculates
  * the time in microseconds required to rise or fall to this new voltage.
  *
- * Drivers providing ramp_delay in regulation_constraints can use this as their
- * set_voltage_time() operation.
+ * Drivers providing ramp_delay or settle_time_up in regulation_constraints
+ * can use this as their set_voltage_time() operation.
  */
 int regulator_set_voltage_time_op(struct regulator_dev *rdev,
 				int old_uV, int new_uV)
 {
+	unsigned int settle_time = 0;
 	unsigned int ramp_delay = 0;
 
+	if (new_uV > old_uV)
+		settle_time = rdev->constraints->settle_time_up;
+
 	if (rdev->constraints->ramp_delay)
 		ramp_delay = rdev->constraints->ramp_delay;
 	else if (rdev->desc->ramp_delay)
 		ramp_delay = rdev->desc->ramp_delay;
 
-	if (ramp_delay == 0) {
-		rdev_warn(rdev, "ramp_delay not set\n");
-		return 0;
-	}
+	if (ramp_delay == 0)
+		return settle_time;
 
-	return DIV_ROUND_UP(abs(new_uV - old_uV), ramp_delay);
+	return settle_time + DIV_ROUND_UP(abs(new_uV - old_uV), ramp_delay);
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage_time_op);
 

@@ -3081,8 +3085,8 @@ EXPORT_SYMBOL_GPL(regulator_set_voltage_time_op);
  * Provided with the starting and target voltage selectors, this function
  * returns time in microseconds required to rise or fall to this new voltage
  *
- * Drivers providing ramp_delay in regulation_constraints can use this as their
- * set_voltage_time_sel() operation.
+ * Drivers providing ramp_delay or settle_time_up in regulation_constraints
+ * can use this as their set_voltage_time_sel() operation.
  */
 int regulator_set_voltage_time_sel(struct regulator_dev *rdev,
 				   unsigned int old_selector,

index 4f613ec..056f242 100644
@@ -90,6 +90,10 @@ static void of_get_regulation_constraints(struct device_node *np,
 	if (!ret)
 		constraints->enable_time = pval;
 
+	ret = of_property_read_u32(np, "regulator-settle-time-up-us", &pval);
+	if (!ret)
+		constraints->settle_time_up = pval;
+
 	constraints->soft_start = of_property_read_bool(np,
 					"regulator-soft-start");
 	ret = of_property_read_u32(np, "regulator-active-discharge", &pval);

index ad3e515..8681a82 100644
@@ -108,6 +108,7 @@ struct regulator_state {
  * @initial_state: Suspend state to set by default.
  * @initial_mode: Mode to set at startup.
  * @ramp_delay: Time to settle down after voltage change (unit: uV/us)
+ * @settle_time_up: Time to settle down after voltage increase (unit: uV/us)
  * @active_discharge: Enable/disable active discharge. The enum
  *		      regulator_active_discharge values are used for
  *		      initialisation.

@@ -150,6 +151,7 @@ struct regulation_constraints {
 
 	unsigned int ramp_delay;
 	unsigned int enable_time;
+	unsigned int settle_time_up;
 
 	unsigned int active_discharge;